SweetSpot lecture series addresses insulin use

According to Dr. Bill Harper, pharmacist at the Medicine Shoppe, insulin use "is not scary, and does a good job of controlling blood sugar."

Harper presented a talk entitled "Insulin 101" as the next installment of the SweetSpot diabetes classes, held the last Wednesday of each month at the McAuley Center. Medications make up one of the legs of the three-legged stool analogy that Harper uses to describe diabetes management, the other two being diet and exercise, and insulin is an important tool in the treatment of both Type 1 and Type 2 diabetes.

Harper began his presentation by answering the question, "What is insulin?" Insulin is a hormone, produced in the pancreas, which circulates in the bloodstream and allows sugar to enter cells.

When blood glucose levels fall, stored sugar is converted to energy, and the process has effects throughout the body.

Diabetes can occur when insulin levels are not controlled.

Type 1 diabetes, in which the pancreas produces little or no insulin, must be controlled with supplemental insulin.

Type 2 diabetes, formerly called "non-insulin dependent" diabetes, is diagnosed when blood-sugar levels are high and insulin resistance or deficiency are indicated, and is often caused by obesity.

The disease can be initially managed by diet and exercise, but if these measures do not sufficiently lower blood-sugar levels, insulin or other medications may be necessary.

Harper said that many Type 2 diabetics use – or should use – insulin.

Insulin used to treat diabetes was initially extracted from animal pancreases, but is now a product of biosynthetic manufacturing. There are several factors that diabetics need to take into consideration regarding insulin use: onset, peak, duration and strength.

Onset refers to the length of time it takes for the insulin to reach the bloodstream and begin working; the peak is the point at which the insulin is working at its maximum ability; duration refers to how long the insulin remains in the body; and strength refers to the dosage amount. In the United States, the strength is usually U-100, or 100 units/ml.

There are several types of insulin, and doctors often prescribe a mixture.

Rapid-acting insulin, such as Humalog, NovoLog or Apidra, begins working in five minutes, peaks in an hour, and lasts two to four hours.

Short-acting (or regular) insulin starts working in 30 minutes, peaks at around two to three hours, and has a three to six hour duration. Typical brands include Humulin R and Novolin R.

Intermediate-acting insulin, usually given with rapid- or short-acting insulin, begins its work in two to four hours, peaks from four to 12 hours, and lasts up to 18 hours.

Examples include NPH and lente.

Long-acting insulin, such as Ultralente, Lantus and Levemir, begins to work in six to 10 hours, lasts about 24 hours, and has no peak. Type 2 diabetics typically start with long-acting insulin.

Pre-mixed insulin – a mixture of two types – is also available, and is usually a combination of 70 percent long-acting and 30 percent rapid-acting insulin. This type helps to regulate blood sugar levels throughout the day, with additional, rapid-acting insulin at meal-times.

Harper noted that pre-mixed insulin can help with vision or dexterity problems. Common brands include Humulin 70/30, Novolin 70/30, NovoLog 70/30 and Humalog 75/25.

Insulin is almost always delivered by injection – it is not taken orally, because it would digest before reaching the bloodstream. Harper mentioned a nasal spray that has been developed, but which, for some reason, has not been popular.

Most insulin users use syringes or pens to inject the insulin. The pen is a little more expensive, but is easy to carry and has a dial to measure the dosage. Insulin pumps are also available, and have advantages and disadvantages.

When asked about re-using needles, Harper said that needle manufacturers say never to re-use a needle, but many diabetics do.

He added that if needles are re-used, they should be capped when not in use, and should not be allowed to touch anything other than skin and the top of the vial. He said never to clean a needle with alcohol or with hot water, throw it away if it becomes dull, and never share with anyone else.

To dispose of used needles, users should consult with local waste disposal agencies, remove needles from syringes, and put in heavy plastic bottles with screw-on caps.

Harper recommended injecting into the same general area every time, but not in the exact same spot. He said that the best place to give an injection is in the fatty tissue of the abdomen (but not close to the navel), where absorption is fastest.

Injection timing is essential to effective insulin use, according to Harper. Correct timing gives the best blood sugar control, prevents hypoglycemia, and allows the body to use the insulin efficiently.

He added that insulin is most effective when it starts working, as glucose from food enters the bloodstream.

Rapid-acting insulin should be delivered within a few minutes of eating, and regular insulin about half an hour before a meal. That’s why it is important to know the onset, peak and duration of each type of insulin taken.

Harper emphasized the need for self-monitoring for all diabetics, and added that insulin-dependent diabetics need to monitor their levels three times a day. He also recommends recording all pertinent data – blood-sugar levels, diet and exercise.

Insulin needs to be refrigerated, but, once opened, it can be kept at room temperature for about a month. Harper reminded the group to always ensure that there are no clumps, crystals or discoloration in the insulin before using, and mentioned some accessories that can keep the insulin cool, for travel, etc.

To close the session, class attendees were offered "diabetes-friendly" fruit skewers, and a drawing was held for diabetes products.

The next installment in the series will be held at 12:30 p.m. Aug. 28 at the McAuley Center.